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Dec. 22 1925 A. J. CARTER DRILLING MACHINE Sheets-Sheet. 1

Filed March 5. 1922 IN VEN TOR. I

DQC- 22, I

A. J. CARTER DRILLING MACHINE Filed Mafoh a. 1922 S eets- She et 2 INVENTQR. A. J. QARTEJ dil Patented 22, 1 925.

mnnnw-acnn'rnn, or Damn, cononano.

DRILLING mom Application filed larch 3,

To all whomit may concern: I c

Be it known that I, ANDREW J. CARTER, a citizen of the United States, residin at Denver, in the county of Denver and tate of Colorado, have invented certain new and useful Improvements in Drilling Machines,

of which the following is a specification.

This invention relates to drilling machines of the type in which a reciprocating hammer is caused to forcibly engage wit the end of a rotating and longitudinally moving drill steel by the expansion of a helical spring against which :it is -intermittently retracted through the instrumentality of a-rotary crank-wheel. I A machine of the above described char-- acter has been shown and described in .United States Letters. Patent Nos. 1,069,853 and 1,115,898 granted to me on the twelfth day of August, 1913, and-on the third day of November, 1914, res ectively, and it is the principal object of t e present invention to provide in the constructions disclosed in the above mentioned patents, certain new improvements which increase the usefulness and efficiency of the machine, and augment its practical value.

Another object of the invention resides in providing for the mechanical operation of the impact mechanism of the drilling machine by an electrically driven motor which is mounted on the machine so .as'to form a component part thereof; a further object is to provide a readily controlled adjustment for varying the stroke of the reciprocating hammer to any desired degree within the limits set by the proportions and relative arrangement of the operative parts of the retraction mechanism; and still another object resides in providing an easily adjusted device of simple construction for pulling the drill steel from the hole in which it works,

' whenthemachine is withdrawn.

similarly designated and An embodiment of my invention has been illustrated in the accom anying drawings in the several views of which like parts are" in which Figure ,1 "is a side elevation of my improved drilling machine in its 0 erative position on a guide shell which, as 1n other 1922.; serial as. 0,911,

inachines of this type, houses the screw by which the machine is advancedc-tgward the face of the rock in ratio to the increasing depth of the hole produced b theintermittent impacts ofthe drill stee Figure 2 represents a longitudinal section of the drilling machine takenv on the planeindicated by the line 22in Figure 3 and, showing the electric motor which as stated before, is mounted on the casing of themachine, in'elevation;

Figure 3, a longitudinal section taken on,

the hne 3-3, Figure 2;

Figure 4, a fragmentarysection alongithe line 44, Figure3; Figure 5, a section on the line 5, Figure 1, looking in the directionfof thearrow drawn across said l ne v Figure 6, a transverse section taken 'on the line 6--6, Figure 2, and Figure 7 an enlarged view of the hook-shaped head of the pull bar of the machine. J Referring more specificall to the --drawin'gs, thereference numeral 2 designates the casing of the machine which, as usual, is composed of bolt-connected sections3y4; and 5 which when taken apart afiord access to the assembled parts of the operating mechanism; I I 1 A shaft 6 mounted for rotation in bearings onvthe sides of the casing at the rear end thereof, carries inside a chamber 7 a crank wheel composed of two aral'lel disks 8 and 9 which are separated y a s acing collar 7 and which are connected a jacent their peripheral edges by a plurality of equidistantly arranged wrist pins 10.

Each Wrist 'pinis provided with a loosely surrounding roller 12 to reduce friction during its contact with the pull bar of the reciprocating hammer as will-hereinafter be described, and it will be understood that although in the-drawings but three wrists have been shown, their number may be in-- creased or decreased according to the frequency of the hammer strokes desired durin each revolution of the shaft.

he disk 9 of the crank wheel is enlarged in thickness and provided with gear teeth for its co-operative engagement with a pinion 13 on a short transverse shaft 14 in the upper portion of the chamber 7, which through the medium of a pair of meshing mitergears 15 and 16, is operatively connected with the shaft of an electric motor contained in a housing 17 which is mounted upon the casing of the drill.

Inasmuch as the construction of the motor is nota part of the present invention, its mechanism has not been shown in the drawings, it bein sufficient for the purpose of explaining t e operation of the improved impact apparatus, to state that its rotor is connected with a suitable reduction gearing inside the housing,of which the protruding shaft onwhich the gear wheel 16 is mounted, is the driven member. v

The cylindrical hammer-chamber 18 of the casing, forward of the crank-chamber 7, is partially lined with a bushing 19 of steel or other wear-resisting material, which can be readily removed and replaced.

Fitted for reciprocation in the lined por tion of the chamber, is a reciprocating ham-.

mer' 20' which is flattened at opposite sides to reduce friction and prevent its binding in the cylindrical guiding'surface.

The hammer is connected at the end of a rearwardly extending pull bar or pitman 21 by means'of a pivot joint which is formed of a transverse cylindrical boss 22 at theend of the rod, rotatably fitted in a correspondingly. formed recessin the rearward portion of the hammer.

The recess is open at one end as shown in Figure 6 of the drawings, and after the pit,- man is in place therein, its end is closed by a plug 23. The pull bar 21 has at its free, rearward end an offset hook-shaped head 24 which in the rotary movement of the shaft- 6, is intermittently engaged by the wrists on the crank-wheel.

A spring-supported prop providesa yielding support for the bar in its operative position, and an adjusting appliance engaging the upper surface of the bar times the periods of its 0 erative engagement with the crank-wheel uring the rotary movement of the shaft.

The yielding support consists of an arm -2.") pivotally attached to the apertured head of a bolt 26 which is secured in an opening in the rear wall of the casing by a nut 27. The arm is supported in an inclined position 11 on a spiral spring 28 which is seated in a epression inthe bottom of the casing and it carries at its free end, an anti-friction roller 29 which engages with the underside of the pitman. e

The stroke-adjusting appliance consists of a transverse shaft 30 rotatably supported in bearings at opposite sides of the crank chamber near its juncture with the hammer chamber, and provided with a forwardly extending arm 31 which engages the upper surface of the bar, and with a crankarm 32 at right angles thereto, which has a pivotal connection with the end of an ad-' it is desired to regulate the operative posi- -tion of the pull bar relative to the crank wheel, by longitudinal adjustment of the screw Interposed between'the hammer and a shoulder at the rear end of the 'hammerchamber, is a helical spring'38 which when compressed by the rearward movement of the hammer through the 1 operative" action of the crank wheel upon the'pull bar, provides the power by which thehammer when subsequently released, is impelled to forcibly engage-with the end of a drill steel 39 longitudinally movably mounted at the for-- ward end of the casing.

The drill steel is held in a chuck 40 which is rotatably supported in a sleeve 41 extending forwardly of the-front head 5 of the easing, and the chuck carries for its rotation in the operation of the machine, a gear wheel 42 which meshes with a pinion 43 at the end of a shaft 44 extending through a bore of the casing formed parallel to the hammer chamber. v I

The shaft whichis supported in bearings at the ends of the bore, is provided with a wormwheel 45 which meshes with a worm. 4.6 on the crank shaft.

In order to feed water to the point of contact of the drill steel with the rock and thereby prevent loss in temper by overheating, the steel has an axial bore through which water supplied at its rearward end inside the casing, may flow to the cuttingedges at its opposite end.

The water is supplied to the bore of the drill steel through a U-shaped tube 47 which extends into the hammer chamber through a slot in the bushin 19 with one of its ends projecting loosely inside the orifice of the I supply.

The steel puller hereinbefore referred to consists of a yoke 52 which straddles .the drill steel forward ofthe sleeve on the front 'head through the medium end of the sleeve on the front head of the casing and which is hinged as at 53,-between lugs at the rear end of the of an angularly displesed arm 54.

e arm has a projection 55 which by fric-h, tional contact with a surface of the head,

holds the yoke against accidental displacement, and a Ii 56 at the point of juncture of the arm wit the yoke pro er is provided to facilitate movin the appliance about its for t e. removal of the drill screw by which the machine is advanced to the work, and the casin of the machine is supported upon a so-ca led mounting slide 59 which by means of a sleeve 60 is operatively connected with the feed screw.

The casing is connected with the slide 59 through the medium of a chain 61 attached at its ends to lugs atthe sides of the slide and placed in a circumferential depression at the rear end of the casing, and links 62 which. are-pivotally connected with the slide and engage over hook-shaped lugs 63 at apposite s1 es of the casing nearer the front 7 end of the same;

Inasmuch as the method of mounting the :machine and the? means for feeding it to 40 the face of the rock, do not diifer materially from those at present used on other machines of similar character, no details thereof have been shown in the drawings, other than those hereinbefore described.

In the operation of the machine, the guide shell is as usual, mounted on a column or other suitable sup ort, and the machine is advanced by rotation ofthe feed screw un- 'til the cutting end of the drill steel engages with the face of the rock. v

' The electric motor which is connected witha conveniently located source of elec: tricity by means of conductors 64 extending through an opening of its housing, is now energized by reversal of a switch controlling the current-flow through its circuit and the movement of its rotor is through the medium of the reduction gearing andthe miter-gears 15 and .16, transmitted to the pinion 13 which b enga ement withthe gear. wheel 9 causes t e cran shaft to rotate in its bearin s at a greatly reduced rate of s ed..

uring the rotary movement 0 the shaft in the direction of the arrow shown in Figure 2, the equidista'ntly arranged waste of its crank wheel will successively engage with Y the hook-shaped head of the pull bar and -therebyv cause the hammer to be retracted the sudden expansion of the spring'forcibly impelled to strike against the end of the drill steel and thereby cause the same to cut into the rock...

I The hammer has in its forward portion, a groove 65 as shown in Figure 3 of thedrawlugs, to admit the curved water tube 47 when it approaches the end of its forward stroke.

It will be understood that while the ma- Iv chine is .in operation, the drill is continuously rotated at a comparativel slow velocity by the rotary movement o the shaft 44 which through the medium of the worm gearing, is compelled to move synchronously with the'crank shaft.

The length of stroke of the hammer may be re lated by adjustment of the arm 31 engaging with the pitman, it being evident that as the latter is lowered, the period between the en agement of its head with each .crank in an its subsequent disen agement from t e same is proportionately s ortened. The spring pressed arm 25 holds the, pull her continuously in engagement with the wrist of the crank wheel and the loose fit of the nut 34 of the adjustment in the opening of the rear wall of the casing, permits of the adjusting screw following the'arcuate movement of the arm 32. when the shaft 30 is moved about its axis of rotation. Y

The steel puller is effective only when the drill steel is withdrawn from the hole roduced in the operation of the machine, w en by engagement with the collar on the steel it compels the latter to.-. move rearwardly with the machine and thereby prevents its sticking in the rock.

Having thus described the several improvements in the construction of my-drillmg machine, in the most practical and simle'st form at present known to me, I desire.

1t understood that variations in the details of construction and the arrangement of their hereunto appended claims.

What I c aim .and desire to secure by Letters Patent is:

1. In a'*-rock drill of the character de scribed, the combination of a spring-urged Ereciprocatin hammer, a pull bar in pivotal connection t erewith, a rotary crank intermittently actin upon the pull bar, a springur d element oosely engaging a side of the pu 1 bar to yieldingly maintain its operative relation with the crank, and an ad ustable sto loosely engaging an exterior face of the pull bar in oppositionto said element to limit the movement of the pull bar by action of the element.

2. In a rock drill of the character described, the combination of a spring-urged reciprocating hammer, a pull bar in pivotal connection therewith, a rotary crank intermittently acting upon the pull bar, a movv able spring urged element loosely engaging a side of the pull bar to yieldingly maintain its operative relation with the crank, a stop capable of pivotal adjustment and loosely engaging the pull bar in opposition to said element, and means to effect the adjustment of the stop.

3. In a rock drill, acasing, a drill steel projectin through an end thereof and provided wit a collar. mechanism in the casing the casing, a yoke on the arm at one side of the pivotal axis, straddling the. steel for en gagement with'its'collar, and a projection on the arm at the. opposite side of the axis, frictionally engaging the casing.

4, In a rock drill, a casing, a. drill projecting through an end thereof and pro vided with a collar, mechanism in the casing for the'operation of the drill steel, and a steel puller comprising an arm pivoted at one end on the casing, a yoke extending angularly at the outer end of the arm and straddling thev steel for engagement with its collar, a projection at the pivoted end of the arm, frictionally engaging the .casing, and a lip at the outer end of the. arm to move it I steel about its pivot against the frictional resistance of the projection.

In testimony whereof I have affixed my signature.

' ANDREW J. CARTER. 

